Hydrocracking process with recycle, comprising adsorption of polyaromatic compounds from the recycled fraction on an adsorbant based on silica-alumina with a limited macropore content

An improved hydrocracking process with a recycle, having a step for eliminating polyaromatic compounds from at least a portion of the recycled fraction by adsorption on an adsorbent based on alumina-silica (i.e. comprising alumina and silica) with a silica (SiO2) content of more than 5% by weight to 95% or less, comprising:

• a mean pore diameter, measured by mercury porosimetry, in the range 20 to 140 Å;
• a total pore volume, measured by mercury porosimetry, in the range 0.1 ml/g to 0.5 ml/g;
• a total pore volume, measured by nitrogen porosimetry, in the range 0.1 ml/g to 0.5 ml/g;
• a BET specific surface area in the range 200 to 600 m2/g;
• a pore volume, measured by mercury porosimetry, included in pores with a diameter of more than 140 Å, of less than 0.1 ml/g;
• a pore volume, measured by mercury porosimetry, included in pores with a diameter of more than 160 Å, of less than 0.1 ml/g;
• a pore volume, measured by mercury porosimetry, included in pores with a diameter of more than 200 Å, of less than 0.1 ml/g;
• a pore volume, measured by mercury porosimetry, included in pores with a diameter of more than 500 Å, of less than 0.1 ml/g;
• an X ray diffraction diagram which contains at least the characteristic principal peaks of at least one transition alumina included in the group composed of rho, khi, kappa, eta, gamma, theta and delta aluminas;
• a catalyst settled packing density of more than 0.75 g/cm3.